1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivatives useful as modulator of nicotinic acetylcholine receptors

ABSTRACT

This invention relates to novel N-oxides of a 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative and their use in the manufacture of pharmaceutical compositions. The compounds of the invention are found to be cholinergic ligands at the nicotinic acetylcholine receptors. Due to their pharmacological profile the compounds of the invention may be useful for the treatment of diseases or disorders as diverse as those related to the cholinergic system of the central nervous system (CNS), the peripheral nervous system (PNS), diseases or disorders related to smooth muscle contraction, endocrine diseases or disorders, diseases or disorders related to neuro-degeneration, diseases or disorders related to inflammation, pain, and withdrawal symptoms caused by the termination of abuse of chemical substances.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Phase of PCT/EP2009/052732 filed onMar. 9, 2009, which claims priority under 35 U.S.C. 119(e) to U.S.Provisional Application No. 61/035,876 filed on Mar. 12, 2008 and under35 U.S.C. 119(a) to Patent Application No. PA 2008 00372 filed inDenmark on Mar. 11, 2008, all of which are hereby expressly incorporatedby reference into the present application.

TECHNICAL FIELD

This invention relates to novel N-oxides of a1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative and their use inthe manufacture of pharmaceutical compositions. The compounds of theinvention are found to be cholinergic ligands at the nicotinicacetylcholine receptors.

Due to their pharmacological profile the compounds of the invention maybe useful for the treatment of diseases or disorders as diverse as thoserelated to the cholinergic system of the central nervous system (CNS),the peripheral nervous system (PNS), diseases or disorders related tosmooth muscle contraction, endocrine diseases or disorders, diseases ordisorders related to neuro-degeneration, diseases or disorders relatedto inflammation, pain, and withdrawal symptoms caused by the terminationof abuse of chemical substances.

BACKGROUND ART

The endogenous cholinergic neurotransmitter, acetylcholine, exert itsbiological effect via two types of cholinergic receptors, the muscarinicAcetyl Choline Receptors (mAChR) and the nicotinic Acetyl CholineReceptors (nAChR).

As it is well established that muscarinic acetylcholine receptorsdominate quantitatively over nicotinic acetylcholine receptors in thebrain area important to memory and cognition, and much research aimed atthe development of agents for the treatment of memory related disordershave focused on the synthesis of muscarinic acetylcholine receptormodulators.

Recently, however, an interest in the development of nAChR modulatorshas emerged. Several diseases are associated with degeneration of thecholinergic system i.e. senile dementia of the Alzheimer type, vasculardementia and cognitive impairment due to the organic brain damagedisease related directly to alcoholism. Indeed several CNS disorders canbe attributed to a cholinergic deficiency, a dopaminergic deficiency, anadrenergic deficiency or a serotonergic deficiency.

WO 2007/138038 describes 1,4-diazabicycloalkane derivatives useful asmodulators of the nicotinic receptors. However, the N-oxide of the1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the presentinvention have not been described.

SUMMARY OF THE INVENTION

The present invention is devoted to the provision novel modulators ofthe nicotinic, which modulators are useful for the treatment of diseasesor disorders related to the cholinergic receptors.

Due to their pharmacological profile the compounds of the invention maybe useful for the treatment of diseases or disorders as diverse as thoserelated to the cholinergic system of the central nervous system (CNS),the peripheral nervous system (PNS), diseases or disorders related tosmooth muscle contraction, endocrine diseases or disorders, diseases ordisorders related to neuro-degeneration, diseases or disorders relatedto inflammation, pain, and withdrawal symptoms caused by the terminationof abuse of chemical substances.

The compounds of the invention may also be useful as diagnostic tools ormonitoring agents in various diagnostic methods, and in particular forin vivo receptor imaging (neuroimaging), and they may be used inlabelled or unlabelled form.

In its first aspect the invention provides novel N-oxides of a1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of Formula I

or a pharmaceutically acceptable salt thereof; wherein

Ar represents a phenyl group, which phenyl is substituted withmethylenedioxy or ethylenedioxy.

In its second aspect the invention provides pharmaceutical compositionscomprising a therapeutically effective amount of the N-oxides of the1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the invention,or a pharmaceutically acceptable addition salt thereof, or a prodrugthereof, together with at least one pharmaceutically acceptable carrieror diluent.

In a further aspect the invention relates to the use of the N-oxides ofthe 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of theinvention, or a pharmaceutically acceptable addition salt thereof, forthe manufacture of a pharmaceutical composition/medicament for thetreatment, prevention or alleviation of a disease or a disorder or acondition of a mammal, including a human, which disease, disorder orcondition is responsive to modulation of cholinergic receptors.

In a final aspect the invention provides methods of treatment,prevention or alleviation of diseases, disorders or conditions of aliving animal body, including a human, which disorder, disease orcondition is responsive to modulation of cholinergic receptors, whichmethod comprises the step of administering to such a living animal bodyin need thereof a therapeutically effective amount of the N-oxides ofthe 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of theinvention.

Other objects of the invention will be apparent to the person skilled inthe art from the following detailed description and examples.

DETAILED DISCLOSURE OF THE INVENTION 1,4-Diaza-bicyclo[3.2.2]nonylOxadiazolyl Derivatives

In a first aspect novel N-oxides of 1,4-diaza-bicyclo[3.2.2]nonyloxadiazolyl derivatives are provided. The N-oxide of the1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the inventionmay be represented by the general Formula I

or a pharmaceutically acceptable salt thereof; wherein Ar represents aphenyl group, which phenyl is substituted with methylenedioxy orethylenedioxy.

In a more preferred embodiment the N-oxides of the1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the invention isa compound of Formula I, or a pharmaceutically acceptable salt thereof,wherein Ar represents a phenyl group substituted with methylenedioxy.

In another more preferred embodiment the N-oxides of the1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the invention isa compound of Formula I, or a pharmaceutically acceptable salt thereof,wherein Ar represents a phenyl group substituted with ethylenedioxy.

In a most preferred embodiment the N-oxide of the1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the invention is

4-(5-Benzo[1,3]dioxol-5-yl-[1,3,4]oxadiazol-2-yl)-1,4-diazabicyclo[3.2.2]-nonane-1-oxide;

or a pharmaceutically acceptable salt thereof.

Any combination of two or more of the embodiments described herein isconsidered within the scope of the present invention.

Pharmaceutically Acceptable Salts

The N-oxides of the 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivativeof the invention may be provided in any form suitable for the intendedadministration. Suitable forms include pharmaceutically (i.e.physiologically) acceptable salts, and pre- or prodrug forms of thecompound of the invention.

Examples of pharmaceutically acceptable addition salts include, withoutlimitation, the non-toxic inorganic and organic acid addition salts suchas the hydrochloride derived from hydrochloric acid, the hydrobromidederived from hydrobromic acid, the nitrate derived from nitric acid, theperchlorate derived from perchloric acid, the phosphate derived fromphosphoric acid, the sulphate derived from sulphuric acid, the formatederived from formic acid, the acetate derived from acetic acid, theaconate derived from aconitic acid, the ascorbate derived from ascorbicacid, the benzenesulphonate derived from benzensulphonic acid, thebenzoate derived from benzoic acid, the cinnamate derived from cinnamicacid, the citrate derived from citric acid, the embonate derived fromembonic acid, the enantate derived from enanthic acid, the fumaratederived from fumaric acid, the glutamate derived from glutamic acid, theglycolate derived from glycolic acid, the lactate derived from lacticacid, the maleate derived from maleic acid, the malonate derived frommalonic acid, the mandelate derived from mandelic acid, themethanesulphonate derived from methane sulphonic acid, thenaphthalene-2-sulphonate derived from naphtalene-2-sulphonic acid, thephthalate derived from phthalic acid, the salicylate derived fromsalicylic acid, the sorbate derived from sorbic acid, the stearatederived from stearic acid, the succinate derived from succinic acid, thetartrate derived from tartaric acid, the toluene-p-sulphonate derivedfrom p-toluene sulphonic acid, and the like. Such salts may be formed byprocedures well known and described in the art.

Other acids such as oxalic acid, which may not be consideredpharmaceutically acceptable, may be useful in the preparation of saltsuseful as intermediates in obtaining a 1,4-diaza-bicyclo[3.2.2]nonyloxadiazolyl derivative of the invention and its pharmaceuticallyacceptable acid addition salt.

Examples of pharmaceutically acceptable cationic salts of a1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the inventioninclude, without limitation, the sodium, the potassium, the calcium, themagnesium, the zinc, the aluminium, the lithium, the choline, thelysine, and the ammonium salt, and the like, of a compound of theinvention containing an anionic group. Such cationic salts may be formedby procedures well known and described in the art.

Additional examples of pharmaceutically acceptable addition saltsinclude, without limitation, the non-toxic inorganic and organic acidaddition salts such as the hydrochloride, the hydrobromide, the nitrate,the perchlorate, the phosphate, the sulphate, the formate, the acetate,the aconate, the ascorbate, the benzenesulphonate, the benzoate, thecinnamate, the citrate, the embonate, the enantate, the fumarate, theglutamate, the glycolate, the lactate, the maleate, the malonate, themandelate, the methanesulphonate, the naphthalene-2-sulphonate derived,the phthalate, the salicylate, the sorbate, the stearate, the succinate,the tartrate, the toluene-p-sulphonate, and the like. Such salts may beformed by procedures well known and described in the art.

Metal salts of a 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative ofthe invention include alkali metal salts, such as the sodium salt of acompound of the invention containing a carboxy group.

In the context of this invention the “onium salts” of N-containingcompounds are also contemplated as pharmaceutically acceptable salts.Preferred “onium salts” include the alkyl-onium salts, thecycloalkyl-onium salts, and the cycloalkylalkyl-onium salts.

Labelled Compounds

The compounds of the invention may be used in their labelled orunlabelled form. In the context of this invention the labelled compoundhas one or more atoms replaced by an atom having an atomic mass or massnumber different from the atomic mass or mass number usually found innature. The labelling will allow easy quantitative detection of saidcompound.

The labelled compounds of the invention may be useful as diagnostictools, radio tracers, or monitoring agents in various diagnosticmethods, and for in vivo receptor imaging.

The labelled isomer of the invention preferably contains at least oneradio-nuclide as a label. Positron emitting radionuclides are allcandidates for usage. In the context of this invention the radionuclideis preferably selected from ²H (deuterium), ³H (tritium), ¹³C, ¹⁴C,¹³¹I, ¹²⁵I, ¹²³I, and ¹⁸F.

The physical method for detecting the labelled isomer of the presentinvention may be selected from Position Emission Tomography (PET),Single Photon Imaging Computed Tomography (SPECT), Magnetic ResonanceSpectroscopy (MRS), Magnetic Resonance Imaging (MRI), and Computed AxialX-ray Tomography (CAT), and combinations thereof.

Methods of Producing 1,4-Diaza-bicyclo[3.2.2]nonyl OxadiazolylDerivatives

The N-oxides of the 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivativeof the invention may be prepared by conventional methods for chemicalsynthesis, e.g. those described in the working examples. The startingmaterials for the processes described in the present application areknown or may readily be prepared by conventional methods fromcommercially available chemicals.

Also one compound of the invention can be converted to another compoundof the invention using conventional methods.

The end products of the reactions described herein may be isolated byconventional techniques, e.g. by extraction, crystallisation,distillation, chroma-tography, etc.

Biological Activity

The present invention is devoted to the provision novel ligands andmodulators of the nicotinic receptors, which ligands and modulators areuseful for the treatment of diseases or disorders related to thecholinergic receptors, and in particular the nicotinic acetylcholinereceptor (nAChR). Preferred compounds of the invention show a pronouncednicotinic acetylcholine α7 receptor subtype selectivity, and show apromising in vivo profile.

Due to their pharmacological profile the compounds of the invention maybe useful for the treatment of diseases or conditions as diverse as CNSrelated diseases, PNS related diseases, diseases related to smoothmuscle contraction, endocrine disorders, diseases related toneuro-degeneration, diseases related to inflammation, pain, andwithdrawal symptoms caused by the termination of abuse of chemicalsubstances.

In a preferred embodiment the compounds of the present invention may beuseful for the treatment, prevention or alleviation of a cognitivedisorder, learning deficit, memory deficits and dysfunction, Down'ssyndrome, Alzheimer's disease, attention deficit, attention deficithyperactivity disorder (ADHD), Tourette's syndrome, psychosis,depression, Bipolar Disorder, mania, manic depression, schizophrenia,cognitive or attention deficits related to schizophrenia, obsessivecompulsive disorders (OCD), panic disorders, eating disorders such asanorexia nervosa, bulimia and obesity, narcolepsy, nociception,AIDS-dementia, senile dementia, autism, Parkinson's disease,Huntington's disease, Amyotrophic Lateral Sclerosis, anxiety, non-OCDanxiety disorders, convulsive disorders, epilepsy, neurodegenerativedisorders, transient anoxia, induced neuro-degeneration, neuropathy,diabetic neuropathy, peripheral dyslexia, tardive dyskinesia,hyperkinesia, mild pain, moderate or severe pain, pain of acute, chronicor recurrent character, pain caused by migraine, postoperative pain,phantom limb pain, inflammatory pain, neuropathic pain, chronicheadache, central pain, pain related to diabetic neuropathy, to posttherapeutic neuralgia, or to peripheral nerve injury, bulimia,post-traumatic syndrome, social phobia, sleeping disorders,pseudodementia, Ganser's syndrome, pre-menstrual syndrome, late lutealphase syndrome, fibromyalgia, chronic fatigue syndrome, mutism,trichotillomania, jet-lag, arrhythmias, smooth muscle contractions,angina pectoris, premature labour, diarrhoea, asthma, tardivedyskinesia, hyperkinesia, premature ejaculation, erectile difficulty,hypertension, inflammatory disorders, inflammatory skin disorders, acne,rosacea, Crohn's disease, inflammatory bowel disease, ulcerativecolitis, diarrhoea, or withdrawal symptoms caused by termination of useof addictive substances, including nicotine containing products such astobacco, opioids such as heroin, cocaine and morphine, benzodiazepinesand benzodiazepine-like drugs, and alcohol.

In a more preferred embodiment the compounds of the invention may beuseful for the treatment, prevention or alleviation of pain, mild ormoderate or severe pain, pain of acute, chronic or recurrent character,pain caused by migraine, postoperative pain, phantom limb pain,inflammatory pain, neuropathic pain, chronic headache, central pain,pain related to diabetic neuropathy, to post therapeutic neuralgia, orto peripheral nerve injury.

In an even more preferred embodiment the compounds of the invention maybe useful for the treatment, prevention or alleviation of diseases,disorders or conditions associated with smooth muscle contractions,convulsive disorders, angina pectoris, premature labour, convulsions,diarrhoea, asthma, epilepsy, tardive dyskinesia, hyperkinesia, prematureejaculation, or erectile difficulty.

In a still more preferred embodiment the compounds of the invention maybe useful for the treatment, prevention or alleviation of aneurodegenerative disorder, transient anoxia, or inducedneuro-degeneration.

In a yet more preferred embodiment the compounds of the invention may beuseful for the treatment, prevention or alleviation of an inflammatorydisorder, inflammatory skin disorder, acne, rosacea, Crohn's disease,inflammatory bowel disease, ulcerative colitis, or diarrhoea.

In a further preferred embodiment the compounds of the invention may beuseful for the treatment, prevention or alleviation of diabeticneuropathy, schizophrenia, cognitive or attentional deficits related toschizophrenia, or depression.

Finally the compounds of the invention may be useful for the treatmentof withdrawal symptoms caused by termination of use of addictivesubstances. Such addictive substances include nicotine containingproducts such as tobacco, opioids such as heroin, cocaine and morphine,benzodiazepines, benzodiazepine-like drugs, and alcohol. Withdrawal fromaddictive substances is in general a traumatic experience characterisedby anxiety and frustration, anger, anxiety, difficulties inconcentrating, restlessness, decreased heart rate and increased appetiteand weight gain.

In this context “treatment” covers treatment, prevention, prophylacticsand alleviation of withdrawal symptoms and abstinence as well astreatment resulting in a voluntary diminished intake of the addictivesubstance.

In another aspect, the compounds of the invention are used as diagnosticagents, e.g. for the identification and localisation of nicotinicreceptors in various tissues.

It is at present contemplated that a suitable dosage of the activepharmaceutical ingredient (API) is within the range of from about 0.1 toabout 1000 mg API per day, more preferred of from about 10 to about 500mg API per day, most preferred of from about 30 to about 100 mg API perday, dependent, however, upon the exact mode of administration, the formin which it is administered, the indication considered, the subject andin particular the body weight of the subject involved, and further thepreference and experience of the physician or veterinarian in charge.

Preferred compounds of the invention show a biological activity in thesub-micromolar and micromolar range, i.e. of from below 1 to about 100μM.

Pharmaceutical Compositions

In another aspect the invention provides novel pharmaceuticalcompositions comprising a therapeutically effective amount of theN-oxide of the 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative ofthe invention.

While a 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of theinvention for use in therapy may be administered in the form of the rawcompound, it is preferred to introduce the active ingredient, optionallyin the form of a physiologically acceptable salt, in a pharmaceuticalcomposition together with one or more adjuvants, excipients, carriers,buffers, diluents, and/or other customary pharmaceutical auxiliaries.

In a preferred embodiment, the invention provides pharmaceuticalcompositions comprising the 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolylderivative of the invention, or a pharmaceutically acceptable salt orderivative thereof, together with one or more pharmaceuticallyacceptable carriers therefore, and, optionally, other therapeutic and/orprophylactic ingredients, know and used in the art. The carrier(s) mustbe “acceptable” in the sense of being compatible with the otheringredients of the formulation and not harmful to the recipient thereof.

The pharmaceutical composition of the invention may be administered byany convenient route, which suits the desired therapy. Preferred routesof administration include oral administration, in particular in tablet,in capsule, in dragè, in powder, or in liquid form, and parenteraladministration, in particular cutaneous, subcutaneous, intramuscular, orintravenous injection. The pharmaceutical composition of the inventioncan be manufactured by any skilled person by use of standard methods andconventional techniques appropriate to the desired formulation. Whendesired, compositions adapted to give sustained release of the activeingredient may be employed.

Pharmaceutical compositions of the invention may be those suitable fororal, rectal, bronchial, nasal, pulmonal, topical (including buccal andsub-lingual), transdermal, vaginal or parenteral (including cutaneous,subcutaneous, intramuscular, intraperitoneal, intravenous,intraarterial, intracerebral, intraocular injection or infusion)administration, or those in a form suitable for administration byinhalation or insufflation, including powders and liquid aerosoladministration, or by sustained release systems. Suitable examples ofsustained release systems include semipermeable matrices of solidhydrophobic polymers containing the compound of the invention, whichmatrices may be in form of shaped articles, e.g. films or microcapsules.

The 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of theinvention, together with a conventional adjuvant, carrier, or diluent,may thus be placed into the form of pharmaceutical compositions and unitdosages thereof. Such forms include solids, and in particular tablets,filled capsules, powder and pellet forms, and liquids, in particularaqueous or non-aqueous solutions, suspensions, emulsions, elixirs, andcapsules filled with the same, all for oral use, suppositories forrectal administration, and sterile injectable solutions for parenteraluse. Such pharmaceutical compositions and unit dosage forms thereof maycomprise conventional ingredients in conventional proportions, with orwithout additional active compounds or principles, and such unit dosageforms may contain any suitable effective amount of the active ingredientcommensurate with the intended daily dosage range to be employed.

The 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the presentinvention can be administered in a wide variety of oral and parenteraldosage forms. It will be obvious to those skilled in the art that thefollowing dosage forms may comprise, as the active component, either acompound of the invention or a pharmaceutically acceptable salt of acompound of the invention.

For preparing pharmaceutical compositions from a1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the presentinvention, pharmaceutically acceptable carriers can be either solid orliquid. Solid form preparations include powders, tablets, pills,capsules, cachets, suppositories, and dispersible granules. A solidcarrier can be one or more substances which may also act as diluents,flavouring agents, solubilizers, lubricants, suspending agents, binders,preservatives, tablet disintegrating agents, or an encapsulatingmaterial.

In powders, the carrier is a finely divided solid, which is in a mixturewith the finely divided active component.

In tablets, the active component is mixed with the carrier having thenecessary binding capacity in suitable proportions and compacted in theshape and size desired.

The powders and tablets preferably contain from five or ten to aboutseventy percent of the active compound. Suitable carriers are magnesiumcarbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin,starch, gelatin, tragacanth, methylcellulose, sodiumcarboxymethylcellulose, a low melting wax, cocoa butter, and the like.The term “preparation” is intended to include the formulation of theactive compound with encapsulating material as carrier providing acapsule in which the active component, with or without carriers, issurrounded by a carrier, which is thus in association with it.Similarly, cachets and lozenges are included. Tablets, powders,capsules, pills, cachets, and lozenges can be used as solid formssuitable for oral administration.

For preparing suppositories, a low melting wax, such as a mixture offatty acid glyceride or cocoa butter, is first melted and the activecomponent is dispersed homogeneously therein, as by stirring. The moltenhomogenous mixture is then poured into convenient sized moulds, allowedto cool, and thereby to solidify.

Compositions suitable for vaginal administration may be presented aspessaries, tampons, creams, gels, pastes, foams or sprays containing inaddition to the active ingredient such carriers as are known in the artto be appropriate.

Liquid preparations include solutions, suspensions, and emulsions, forexample, water or water-propylene glycol solutions. For example,parenteral injection liquid preparations can be formulated as solutionsin aqueous polyethylene glycol solution.

The 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative according tothe present invention may thus be formulated for parenteraladministration (e.g. by injection, for example bolus injection orcontinuous infusion) and may be presented in unit dose form in ampoules,pre-filled syringes, small volume infusion or in multi-dose containerswith an added preservative. The compositions may take such forms assuspensions, solutions, or emulsions in oily or aqueous vehicles, andmay contain formulation agents such as suspending, stabilising and/ordispersing agents. Alternatively, the active ingredient may be in powderform, obtained by aseptic isolation of sterile solid or bylyophilization from solution, for constitution with a suitable vehicle,e.g. sterile, pyrogen-free water, before use.

Aqueous solutions suitable for oral use can be prepared by dissolvingthe active component in water and adding suitable colorants, flavours,stabilising and thickening agents, as desired.

Aqueous suspensions suitable for oral use can be made by dispersing thefinely divided active component in water with viscous material, such asnatural or synthetic gums, resins, methylcellulose, sodiumcarboxymethylcellulose, or other well known suspending agents.

Also included are solid form preparations, intended for conversionshortly before use to liquid form preparations for oral administration.Such liquid forms include solutions, suspensions, and emulsions. Inaddition to the active component such preparations may comprisecolorants, flavours, stabilisers, buffers, artificial and naturalsweeteners, dispersants, thickeners, solubilizing agents, and the like.

For topical administration to the epidermis the1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the inventionmay be formulated as ointments, creams or lotions, or as a transdermalpatch. Ointments and creams may, for example, be formulated with anaqueous or oily base with the addition of suitable thickening and/orgelling agents. Lotions may be formulated with an aqueous or oily baseand will in general also contain one or more emulsifying agents,stabilising agents, dispersing agents, suspending agents, thickeningagents, or colouring agents.

Compositions suitable for topical administration in the mouth includelozenges comprising the active agent in a flavoured base, usuallysucrose and acacia or tragacanth; pastilles comprising the activeingredient in an inert base such as gelatin and glycerine or sucrose andacacia; and mouthwashes comprising the active ingredient in a suitableliquid carrier.

Solutions or suspensions are applied directly to the nasal cavity byconventional means, for example with a dropper, pipette or spray. Thecompositions may be provided in single or multi-dose form.

Administration to the respiratory tract may also be achieved by means ofan aerosol formulation in which the active ingredient is provided in apressurised pack with a suitable propellant such as a chlorofluorocarbon(CFC) for example dichlorodifluoromethane, trichlorofluoromethane, ordichlorotetrafluoroethane, carbon dioxide, or other suitable gas. Theaerosol may conveniently also contain a surfactant such as lecithin. Thedose of drug may be controlled by provision of a metered valve.

Alternatively the active ingredients may be provided in the form of adry powder, for example a powder mix of the compound in a suitablepowder base such as lactose, starch, starch derivatives such ashydroxypropylmethyl cellulose and polyvinylpyrrolidone (PVP).Conveniently the powder carrier will form a gel in the nasal cavity. Thepowder composition may be presented in unit dose form for example incapsules or cartridges of, e.g., gelatin, or blister packs from whichthe powder may be administered by means of an inhaler.

In compositions intended for administration to the respiratory tract,including intranasal compositions, the compound will generally have asmall particle size for example of the order of 5 microns or less. Sucha particle size may be obtained by means known in the art, for exampleby micronization.

When desired, compositions adapted to give sustained release of theactive ingredient may be employed.

The pharmaceutical preparations are preferably in unit dosage forms. Insuch form, the preparation is subdivided into unit doses containingappropriate quantities of the active component. The unit dosage form canbe a packaged preparation, the package containing discrete quantities ofpreparation, such as packaged tablets, capsules, and powders in vials orampoules. Also, the unit dosage form can be a capsule, tablet, cachet,or lozenge itself, or it can be the appropriate number of any of thesein packaged form.

Tablets or capsules for oral administration and liquids for intravenousadministration and continuous infusion are preferred compositions.

Further details on techniques for formulation and administration may befound in the latest edition of Remington's Pharmaceutical Sciences(Maack Publishing Co., Easton, Pa.).

A therapeutically effective dose refers to that amount of activeingredient, which ameliorates the symptoms or condition. Therapeuticefficacy and toxicity, e.g. ED₅₀ and LD₅₀, may be determined by standardpharmacological procedures in cell cultures or experimental animals. Thedose ratio between therapeutic and toxic effects is the therapeuticindex and may be expressed by the ratio LD₅₀/ED₅₀. Pharmaceuticalcompositions exhibiting large therapeutic indexes are preferred.

The dose administered must of course be carefully adjusted to the age,weight and condition of the individual being treated, as well as theroute of administration, dosage form and regimen, and the resultdesired, and the exact dosage should of course be determined by thepractitioner.

The actual dosage depends on the nature and severity of the diseasebeing treated, and is within the discretion of the physician, and may bevaried by titration of the dosage to the particular circumstances ofthis invention to produce the desired therapeutic effect. However, it ispresently contemplated that pharmaceutical compositions containing offrom about 0.1 to about 500 mg of active ingredient per individual dose,preferably of from about 1 to about 100 mg, most preferred of from about1 to about 10 mg, are suitable for therapeutic treatments.

The active ingredient may be administered in one or several doses perday. A satisfactory result can, in certain instances, be obtained at adosage as low as 0.1 μg/kg i.v. and 1 μg/kg p.o. The upper limit of thedosage range is presently considered to be about 10 mg/kg i.v. and 100mg/kg p.o. Preferred ranges are from about 0.1 μg/kg to about 10mg/kg/day i.v., and from about 1 μg/kg to about 100 mg/kg/day p.o.

Methods of Therapy

The 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivatives of the presentinvention are valuable nicotinic, and therefore useful for the treatmentof a range of ailments involving cholinergic dysfunction as well as arange of disorders responsive to the action of nAChR modulators.

In another aspect the invention provides a method for the treatment,prevention or alleviation of a disease or a disorder or a condition of aliving animal body, including a human, which disease, disorder orcondition is responsive to modulation of cholinergic receptors, andwhich method comprises administering to such a living animal body,including a human, in need thereof an effective amount of a1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl derivative of the invention.

In a preferred embodiment, the disease, disorder or condition relates tothe central nervous system.

The preferred medical indications contemplated according to theinvention are those stated above.

It is at present contemplated that suitable dosage ranges are within 0.1to 1000 milligrams daily, preferably 10 to 500 milligrams daily, andmore preferred of from 30 to 100 milligrams daily, dependent as usualupon the exact mode of administration, form in which administered, theindication toward which the administration is directed, the subjectinvolved, the body weight of the subject involved, and further thepreference and experience of the physician or veterinarian in charge.

EXAMPLES

The invention is further illustrated with reference to the followingexamples, which are not intended to be in any way limiting to the scopeof the invention as claimed.

Example 1 Preparatory Example

All reactions involving air sensitive reagents or intermediates wereperformed under nitrogen and in anhydrous solvents. Magnesium sulfatewas used as drying agent in the workup-procedures and solvents wereevaporated under reduced pressure.

4-(5-Benzo[1,3]-dioxol-5-yl-[1,3,4]oxadiazol-2-yl)-1,4-diazabicyclo[3.2.2]-nonane-1-oxideCompound 1

4-(5-Benzo[1,3]dioxol-5-yl-[1,3,4]oxadiazol-2-yl)-1,4-diaza-bicyclo[3.2.2]nonane(1.0 g, 3.2 mmol) was solved in ethanol (10 ml, 99%). Hydrogenperoxide(10 ml, 31.82 mmol, 30 wt %) was added dropwise and was stirred for 15 hat room-temperature. The precipitated product was filtered and waswashed with ethanol. The product was dried under vacuum for 15 h. Yield0.50 g (48%). LC-ESI-HRMS of [M+H]+ shows 331.1391 Da. Calc. 331.140631Da, dev. −4.6 ppm.

4-(5-Benzo[1,3]dioxol-5-yl-[1,3,4]oxadiazol-2-yl)-1,4-diaza-bicyclo[3.2.2]nonanefumaric acid salt (Intermediate compound)

A mixture of 1,4-diazabicyclo[3.2.2]nonane (6.36 g, 50.4 mmol),2-benzo[1,3]dioxol-5-yl-5-benzylsulfanyl-[1,3,4]oxadiazole (15.0 g, 48.0mmol), DMF (20 ml) and N,N-diisopropylethylamine (13.0 g, 100.8 mmol)was stirred at 100° C. for 20 hours. Chromatography on silica gel withchloroform, 10% methanol and 1% aqueous ammonia as solvent gave a crudeproduct (7.9 g). Repeated chromatography on silica gel with chloroform,10% methanol and 1% aqueous ammonia as solvent gave the product as anamorphous solid. Yield 4.4 g (29%). The corresponding salt was obtainedby addition of a diethyl ether and methanol mixture (9:1) saturated withfumaric acid. The product fumarate salt was recrystallized fromisopropanol. Yield from free base 3.2 g (61%). LC-ESI-HRMS of [M+H]+shows 315.1463 Da. Calc. 315.145716 Da, dev. 1.9 ppm.

2-Benzo[1,3]-dioxol-5-yl-5-benzylsulfanyl-[1,3,4]oxadiazole(Intermediate compound)

Benzylbromide (20.2 g, 118.1 mmol) was added over 5 minutes time-periodto a mixture of 5-benzo[1,3]dioxol-5-yl-[1,3,4]oxadiazole-2-thiol (25 g,112.5 mmol), trietylamine (22.8 g, 225 mmol) and ethanol (200 ml, 99%).The reaction mixture was stirred at room-temperature for 2 hours.Aqueous sodium hydroxide (150 ml, 1 M) and water (100 ml) was addedfollowed by filtration. The product was isolated as a solid. Yield 31.0g (94%).

5-Benzo[1,3]dioxol-5-yl-[1,3,4]oxadiazole-2-thiol (Intermediatecompound)

Benzo[1,3]dioxole-5-carboxylic acid hydrazide (45.8 g, 254 mmol) wasadded to a mixture of potassium hydroxide (15.7 g, 280 mmol) andmethanol (350 ml). The mixture was stirred for 30 minutes at roomtemperature. Carbon disulfide (38.7 g, 508 mmol) was added. The mixturewas stirred at reflux for 20 hours, followed by another portion ofcarbon disulfide (12.7 g, 167 mmol) and reflux for 4 h. Water (300 ml)was added and the excess of carbon disulfide and methanol wasevaporated. The aqueous suspension was acidified by adding concentratedhydrochloric acid to pH 3-4. The product precipitated, filtered and waswashed with water (50 ml). Yield 53.5 g (95%) as yellow powder.

Benzo[1,3]dioxole-5-carboxylic acid hydrazide (Intermediate compound)

A mixture of benzo[1,3]dioxole-5-carboxylic acid (42.7 g, 257.0 mmol)and thionylchloride (163 g, 1.36 mol) was stirred at 65° C. for 6 days.The mixture of benzo[1,3]dioxole-5-carbonyl chloride was evaporated,solved in tetrahydrofuran (200 ml) and added to a mixture of hydrazinemonohydrate (154.4 g, 3.08 mol) and tetrahydrofuran (250 ml) at −25° C.,followed by stirring for 0.5 hours at −25° C. Water (200 ml) was addedfollowed by filtration. Solid material (35.0 g) was isolated byfiltration and another portion of solid material (10.8 g) was isolatedby extraction of the filtrate with ethyl acetate, followed by drying andevaporation. Yield 45.8 g (99%).

Example 2 Ex Vivo Inhibition of ³H-α-Bungarotoxine Binding inHippocampal Membranes

In this example the affinity of the compounds of the invention forbinding to α₇-subtype of nicotinic receptors is determined.

α-Bungarotoxine is a peptide isolated from the venom of the Elapidaesnake Bungarus multicinctus. It has high affinity for neuronal andneuromuscular nicotinic receptors, where it acts as a potent antagonist.

³H-α-Bungarotoxine labels nicotinic acetylcholine receptors formed bythe α₇ subunit isoform found in brain and the α₁ isoform in theneuromuscular junction.

Tissue Preparation

At a predetermined time point after injection mice are killed bydecapitation, the hippocampi rapidly dissected on ice and the tissue peranimal is weighed. Preparations are performed at 0-4° C. unlessotherwise indicated. The individual hippocampi (2 per animal) arehomogenized for 10 sec in 75 volumes of ice-cold 20 mM Hepes buffercontaining 118 mM NaCl, 4.8 mM KCl, 1.2 mM MgSO₄ and 2.5 mM CaCl₂containing 0.01% BSA (pH 7.5) using an Ultra-Turrax homogenizer. Thetissue suspension is used for binding assays.

Assay

Aliquots of 500 μl homogenate are added to 25 μl of test solution and 25μl of ³H-α-bungarotoxin (1 nM, final concentration), mixed and incubatedfor 2 h at 37° C. Non-specific binding is determined using (−)-nicotine(1 mM, final concentration). After incubation, the samples are added 5ml of ice-cold Hepes buffer containing 0.05% PEI and poured directlyonto Whatman GF/C glass fibre filters (pre-soaked in 0.1% PEI for atleast ½ h) under suction and immediately washed with 2×5 ml ice-coldbuffer.

The amount of radioactivity on the filters is determined by conventionalliquid scintillation counting. Specific binding is total binding minusnon-specific binding.

The test value is given as an ED₅₀ (the dose (mg/kg) of the testsubstance which inhibits the specific binding of ³H-α-bungarotoxin by50%). Three doses of test substance are used to determine the doseresponse curve from which the ED₅₀ value is determined. If a full curveis not available a 25-75% inhibition of specific binding must beobtained before calculation of an ED₅₀ value.

The results of these experiments are presented in Table 1 below.

TABLE 1 Inhibition of ³H-α-Bungarotoxine Binding Compound EC₅₀ (mg/kg) 11.5

1. An N-oxide of a 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl compoundrepresented by Formula I

or a pharmaceutically acceptable salt thereof; wherein Ar represents aphenyl group, which phenyl is substituted with methylenedioxy orethylenedioxy.
 2. The N-oxide of the 1,4-diaza-bicyclo[3.2.2]nonyloxadiazolyl compound of claim 1, or a pharmaceutically acceptable saltthereof, wherein Ar represents a phenyl group substituted withmethylenedioxy.
 3. The N-oxide of the 1,4-diaza-bicyclo[3.2.2]nonyloxadiazolyl compound of claim 1, or a pharmaceutically acceptable saltthereof, wherein Ar represents a phenyl group substituted withethylenedioxy.
 4. The N-oxide of the 1,4-diaza-bicyclo[3.2.2]nonyloxadiazolyl compound of claim 1, which is4-(5-Benzo[1,3]dioxol-5-yl-[1,3,4]oxadiazol-2-yl)-1,4-diazabicyclo[3.2.2]-nonane-1-oxideor a pharmaceutically acceptable salt thereof.
 5. A pharmaceuticalcomposition comprising a therapeutically effective amount of the N-oxideof the 1,4-diaza-bicyclo[3.2.2]nonyl oxadiazolyl compound of claim 1, ora pharmaceutically acceptable addition salt thereof, together with atleast one pharmaceutically acceptable carrier or diluent.